The present invention relates to a transmission between a motor member and a drive shaft of an automotive tractor engine with an accompanying driver walking behind the engine, this driver acting on the steering member of the engine, such as a handlebar, as well as a driving engine provided with such a transmission.
It relates more particularly to a transmission of the type comprising, in a housing, a friction clutch constituted by at least one rotating drive element and at least one driven element carried by the drive output shaft and kinematically secured in rotation with this latter, these driving and driven element coming into bearing contact with variable engagement to obtain a variation of the couple transmitted to the output drive shaft, such as a wheel drive shaft, under the action of a control device projecting at least partially from the housing.
Transmissions of the mentioned type are well known to those skilled in this art. Generally, the control devices coupled to the friction clutch do not permit using the function of varying the speed of clutching.
An object of the present invention is to provide a transmission of the mentioned type whose design permits incorporating a control device permitting a variation of speed of the engine whilst permitting the driver to control automatically the speed of the engine by automatically controlling the speed change arising from terrain of varied profile such as rising and falling.
Another object of the present invention is to provide a transmission of simple design at a reasonable cost.
To this end, the invention has for its object a transmission between a drive member and a drive shaft of an automotive tractor engine with a driver walking behind the engine, this driver acting on a steering member for the engine, such as handlebars, the transmission comprising, in a housing, a friction clutch of the type constituted by at least one rotatable driving element and at least one driven element carried by the output drive shaft and kinematically secured in rotation with this latter, these driving and driven element coming into bearing contact with a variable grip to obtain a variation in the couple transmitted to the output drive shaft, such as a wheel drive shaft, under the action of a control device that at least partially projects from the housing, characterized in that the control device is automatically actuated by two separate inertial forces, one, generated by the driver of the engine, tending to bring together the driving and driven element to increase the couple transmitted when the resistance to forward movement of the engine increases, the other, generated by the mass of the engine relieved by the driver, tending to uncouple the driving and driven element to reduce the couple transmitted when the resistance to advance of the engine decreases.
The invention also has for its object a driven tractor engine with an accompanying driver, the driver walking behind the engine acting on a steering member for the engine such as handlebars, this driving engine incorporating between a motor member and a drive shaft a transmission, the transmission comprising, in a housing, a friction clutch of the type constituted by at least one rotatable driving element and at least one driven element carried by the drive output shaft and kinematically secured in rotation with this latter, these driving and driven element coming into bearing contact with a variable grip to obtain the variation of the couple transmitted to the output drive shaft, such as a wheel drive shaft, under the action of a control device at least partially projecting from the housing, characterized in that the transmission is of the mentioned type.